Image sensors receive light into an array of photosensitive pixels. Each pixel may be formed of a number of cooperating elements including, for example, a lens, often called a “microlens.”, a color filter which blocks all but one color from reaching the photosensitive portion, and the photosensitive portion itself. These elements are typically formed on different physical levels of a substrate.
It has typically been considered that the elements of the pixels should have their centers substantially exactly aligned. That is, the microlens, the color filter, and the photosensitive portion should each be substantially coaxial. The physical process used to create the semiconductor will have inherent errors, however, conventional wisdom attempts to minimize these errors.